RU2769711C1 - Line for producing silica woven materials by leaching method - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: invention relates to equipment for production of fiberglass predominantly high-temperature-resistant silica fabrics by leaching method. The line for the production of silica woven materials by the leaching method includes a device for unwinding a roll, a pre-wetting bath, successively located acid leaching baths, compensators, a fabric pre-sizing unit, devices for intermediate and final washing of fabric from acid, wringer rolls, a drying chamber and a device for winding the finished product. material. At the same time, non-driven arc and driven screw expanders, rotating in the direction opposite to the movement of the fabric, are installed on the tissue sample from each bath with compensators. In front of the entrance to the first and subsequent baths with compensators, tissue guides and non-driven screw spreaders are installed, which ensure uniform sampling from the baths and wiring along the nodes of the processed tissue line at a speed of more than 100 m/h without sagging, displacement and damage.

EFFECT: invention makes it possible to increase the speed of guiding and productivity of the line, to exclude deformations and damages of the fabric in the process of guiding through the nodes of the line and to expand the range and width of the processed fabric.

3 cl, 2 tbl, 2 dwg

Description

Technical field

The invention relates to non-standard equipment for the production of fiberglass predominantly high-temperature-resistant silica fabrics by leaching and can be used at enterprises producing glass fiber materials.

State of the art

The leaching method consists in processing glass fiber materials containing low-melting oxides (for example, Na ₂ O, K ₂ O, etc.) in significant quantities and having a melting point from 500 ° C to 800 ° C, in hot solutions of mineral acids (H ₂ SO ₄ , HCl, etc.). As a result of this treatment, selective removal (leaching) of these fusible oxides occurs due to ongoing exchange reactions, and the materials are enriched with silicon oxide (SiO ₂ ). The melting temperature of such leached materials increases to (1650-1700)°C.

From the patent and technical literature it is known that the leaching of woven materials can be carried out in a continuous or discontinuous manner. In the batch method, the fabric is processed in a mass (roll), which can simply be immersed in the working agent (acid solution or water during washing) and held for a predetermined time, or the working agent can be pumped through a layer of material. The second processing option provides a more homogeneous material and reduces the time of its processing and cleaning.

In the continuous method, the fabric web in straightening passes successively at a certain speed through acid baths, washing baths and a drying chamber.

A device for continuous processing of glass fiber woven materials is known (AS 1636365, class C03C 25/06, publ. 23.03.91), including a solution bath and V-shaped guides located at an equal distance from each other and forming a plane for placement of the processed material, a heat exchanger located under the guides and attached to the latter at an angle of 10-90°, and the angle between the sides of the guides is 20-120°.

The disadvantage of this device is that it can only be a separate node in the technological line for continuous processing of fabric, through which it is possible to intensify the leaching process only in this particular node. This device does not solve the problems of guiding the fabric through all the nodes of such a line at the proposed speeds.

Known production line for continuous processing of fiberglass woven materials (AC 1737053, CL D06B 21/00, publ. 30.05.92 - prototype), containing a device for unwinding the fabric, a pre-wetting bath, three consecutive acid leaching baths, compensators for laying fabric in the form of folds in the last two acid baths, wringer rolls, intermediate washing baths, devices for preliminary and final washing, a drying chamber, a fabric heat treatment agent.

The disadvantage of this line is the limited capacity of all nodes of the line, which do not allow to increase the speed of the wire of the fabric above 60 m/h for fabrics with a surface weight of 100 to 1100 g/m ² due to deformation and displacement of the fabric along the nodes of the line. The dimensions of the line also do not allow processing fabrics with a width of more than 90 cm.

When processing on this line at a speed of ≥60 m/h, the fabric is displaced on the shafts, longitudinal folds are formed, especially in fabrics with a movable structure such as КТ-11-С8/3. With manual alignment and centering, the fabric is deformed and damaged, the fabric is separated, distortions occur.

The technical result of the present invention is to increase the speed and productivity of the line, the exclusion of deformation and damage to the fabric in the process of wiring the nodes of the line, the expansion of the range and width of the processed fabric.

The technical result is achieved due to the fact that the line for producing silica woven materials by the leaching method includes a device for unwinding a roll, a pre-wetting bath, successively located acid leaching baths, compensators, a fabric sizing unit, devices for intermediate and final washing of fabric from acid, wringers shafts, a drying chamber and a device for winding the finished material, while on the sample of fabric from each bath with compensators, non-driven arc and driven screw, rotating in the direction opposite to the movement of the fabric, spreaders are installed, and before entering the first and subsequent baths with compensators, fabric guides are installed and non-driven screw spreaders, providing uniform sampling from the baths and wiring along the nodes of the processed fabric line at a speed of more than 100 m/h without sagging, displacement and damage; and into the tissue bath in the form of folds, the acid baths are installed at different heights relative to each other, decreasing from the last to the first acid bath, and are connected to each other by acid pipelines, through which the acid solution continuously supplied to the last bath flows by gravity into the previous baths, and from the first bath, part of the solution is drained into the neutralizer, ensuring the establishment of equilibrium concentrations of acid and reaction products in the working solutions, a stable and low residual content of fusible oxides in the tissue, as well as the continuity of the installation for a long time without replacing the working solution in the baths.

Disclosure of invention

On fig. 1 and 2 show a flow diagram of a line according to the invention.

The line includes:

a) fig. 1 - a rolling machine (1), a bath for pre-wetting the fabric with a solution of sulfuric acid (2), a roller acid leaching bath (3), three acid leaching baths with tray compensators (4, 5, 6) for laying fabric in the form of folds, fabric guides ( 7), intermediate washing devices (8), final fabric washing devices (9), fabric pre-sizing unit (10), dryers (11), trough compensator (13), reeling machine (12);

b) fig. 2 - pull squeezing pairs (14), lever compensators (15), arc (16) and screw (17) spreaders, a system of driven and freely rotating rollers and rollers (18), stackers (19).

According to the invention, the line operates as follows.

The original glass fabric is installed on the rolling machine (1). With the help of a pull pair, the fabric is unwound and fed to the line or to the tray compensator (13), designed to accumulate fabric when changing the roll without stopping the line at high speeds. Next, the fabric passes through a lever compensator (15), a fabric guide (7) and a pulling squeezing pair (14) is fed into a pre-wetting bath (2) with a sulfuric acid solution with a concentration of 6 to 10 N and a temperature of 10°C to 20°C. Passing over the rollers, the fabric is impregnated with an acid solution and, without wringing out, enters the roller acid bath (3) with a hot sulfuric acid solution with a concentration of about 3 N and a temperature of 90°C to 96°C. In this bath, the fabric is moved into a loop spreader and about 50% of the sodium oxide is removed from it by leaching. At the exit from the bath (3), the fabric is squeezed out and a pull pair (14) is fed into the first acid bath (4) with a trough compensator. Laying the fabric on the compensator is carried out with the help of a baffle stacker (19) installed at the fabric inlet to the bath. The chipper-stacker (19), made in the form of a squirrel wheel, ensures continuous uniform laying of the fabric on the compensator in the form of folds in a given amount. The fabric, leaching, moves along the compensator in a free state without tension and is continuously selected from the bath. Arc (16) and screw (17) spreaders are installed at the exit from the bath, which tighten the middle of the fabric, eliminating sagging and warping of the fabric, straighten and expand it to its original width. The arc spreader (16) is non-driven and rotates with the tissue, the screw spreader (17) is driven and rotates in the direction opposite to the movement of the tissue.

After the intermediate washing device (8), where the fabric is washed from the acid solution and reaction products, it first falls on the tissue guide (7), which is centered, then on the non-driven screw spreader (17) and is fed by a pull pair to the bump stacker (19), installed above the second acid bath (5) with flume expansion joint. In the manner described above, the fabric passes the second (5) and third (6) acid baths with compensators and the intermediate washing device (8) and enters the final washing device (9) with tap water.

The amount of fabric laid on the compensator in each acid bath depends on the mass of a linear meter of fabric and the speed of its wiring and ranges from 10 to 60 meters or more, providing the necessary time for the fabric to stay in solution and the required degree of leaching in this bath. The concentration of the sulfuric acid solution in the baths with compensators is from 2 to 3 N, the temperature is from 90°C to 96°C.

In the final cleaning device (9), the fabric passes through the shower assembly and wringer rolls to improve acid cleaning. At the end of washing, the fabric after the squeezing pair (14), if necessary, enters the fabric subsizing unit (10), where it is impregnated with a water-emulsion composition. Then the fabric is fed to the dryer (11), where it is centered at the inlet with the help of a fabric guide (7). Passing through the dryer (11), the fabric is blown with hot air and dried. After the dryer (11), the fabric is again centered with the fabric guide (7) and wound into a roll on the winder (12).

The speed of the fabric passing through the nodes of the line is from 100 to 300 m/h. On the line, thanks to a system of installed arc (16) and screw (17) spreaders on a sample of fabric from acid baths with compensators, tissue guides, screw expanders (17) and fenders-stackers (19) at the entrance to acid baths with compensators, according to the invention, uniform wiring is provided fabric along the nodes of the line without sagging, displacements, distortions, deformation and damage, manual dressing of the fabric at high speeds of wiring is almost completely excluded, and the possibility of processing fabric up to 130 cm wide is provided.

Line according to the invention of continuous operation. The continuous operation of the line is ensured by the fact that the last acid bath (6) with a compensator is continuously supplied with a solution of sulfuric acid with a temperature of not more than 20 ° C during the entire operation time. The acid baths are installed at different heights, which decreases from the last bath to the first bath connected to each other by overflow pipelines. As a result, part of the solution from the bath (6) flows by gravity into the bath (5), then into the bath (4) and the bath (3). From the bath (3) the excess solution is continuously drained into the neutralizer. The concentration of the solution supplied to the bath and its amount depend on the mass of 1 m ^{2 of} the processed fabric and the speed of the wiring and are determined by calculation.

With such a technological scheme, equilibrium concentrations of acid and reaction products (Na ⁺ ions) are established in the working solutions of acid baths, due to which the solutions can work for a long time (up to a month) without replacement, and the fabric has a stable and low residual content of low-melting oxides throughout the entire period. work. More often, a solution change can be carried out only for a preventive purpose.

Examples of fabric processing on the line according to the invention and according to the prototype are shown in Tables 1 and 2. For greater clarity, a satin weave fabric is presented, which has the most mobile structure compared to plain, twill and other types of weave fabrics.

As can be seen from Table 1, the fabric processed on the line according to the invention at a speed of up to 300 m/h, with close values of processing parameters and physical and mechanical properties, has practically no defects in appearance associated with the passage of the fabric along the nodes of the line, the fabric is not deformed, without distortions, folds and sagging, in contrast to the fabric processed on the line according to the prototype at a speed of up to 100 m/h.

The data of Table 2 show that the concentration of H ₂ SO ₄ and reaction products (Na ₂ O) in acid bath solutions remained practically unchanged over 30 days of continuous operation, ensuring the stability of the leaching process and low and stable values of the residual content of Na ₂ O in the tissue.

Thus, the proposed line of continuous operation, due to the constructive solution of individual components and parts, as well as their layout, will increase the speed of fabric passage, stabilize the leaching process, obtain high-quality fabric in terms of the mass fraction of Na ₂ O, and also in appearance without distortions, sagging, deformations and defects associated with the wiring of the fabric along the line, expand the range, increase productivity and, consequently, reduce the cost of production.

Examples of obtaining a satin weave fabric type KT-11C8 / 3 by leaching on the line according to the invention and prototype

Characteristics of working solutions of sulfuric acid in the acid baths of the line and the residual content of Na ₂ O in the fabric treated in the line according to the invention after 1 and 30 days of operation without changing the solution

Claims (3)

1. A line for the production of silica woven materials by leaching, including a device for unwinding a roll, a pre-wetting bath, successively located acid leaching baths, compensators, a fabric pre-sizing unit, devices for intermediate and final washing of fabric from acid, wringing rollers, a drying chamber, a device for winding the finished material, characterized in that on the sample of fabric from each bath with compensators, non-driven arc and driven screw expanders rotating in the direction opposite to the movement of the fabric are installed, and before entering each bath with a compensator, tissue guides and non-driven screw spreaders are installed, providing uniform sampling from baths and wiring along the nodes of the line of the processed fabric at a speed of more than 100 m/h without sagging, displacement and damage. 2. The line according to claim 1, characterized in that at the entrance to each bath with a compensator, a stacker is installed for uniform laying of fabric in the form of folds into the bath. 3. The line according to claim 1, characterized in that the acid baths are installed at different heights relative to each other, decreasing from the last to the first acid bath, and are connected to each other by acid pipelines, through which the acid solution continuously supplied to the last bath flows by gravity into the previous baths, and from the first bath part of the solution is drained into the neutralizer, ensuring the establishment of equilibrium concentrations of acid and reaction products in the working solutions, a stable and low residual content of low-melting oxides in the tissue, as well as the continuity of the installation for a long time without replacing the working solution in baths.

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